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Memory Beta, non-canon Star Trek Wiki

"Obsession" was the 47th episode of Star Trek: The Original Series.



Episode characters

BardoliChristine ChapelPavel ChekovDikironium cloud creatureStephen GarrovickBill HadleyJames T. KirkRyan LeslieLeonard McCoyRizzoMontgomery ScottSpockSwensonNyota UhuraVinci[1]

Novelization characters

BardoliChristine ChapelDikironium cloud creatureDavid GarrovickJames T. KirkLeonard McCoyRizzoMontgomery ScottSpockSwansonNyota Uhura

Starships and vehicles

USS Enterprise (Constitution-class heavy cruiser)
Referenced only
USS Farragut (Constitution-class heavy cruiser)


Argus XTycho IV

Races and cultures

HumanVulcanDikironium cloud creature

Science and classification

anatomylifeformlogicmattermemoryorbitquadrantraces and culturesspacestarstardatetechnologyuniverseweapon

Technology and weapons


Materials and substances



humanoidDikironium cloud creature

States and organizations


Ranks and titles

captaincommandercommanding officercommunications officerFederation Starfleet ranksFederation Starfleet ranks (2260s)first officerlieutenant commanderofficerscientistscience officer

Other references

armbootclothingFederation membersfingerfive-year missiongovernmenthumanoidlanguagenation-statepantsrankStarfleet uniformStarfleet uniform (2260s)titletunicuniform


Related media

  • This story is one week before the events of the beginning of Best Defense where Kirk is still preoccupied by memories of the event and he compares the situation with what happens to Number One in the Book.


Video releases


According to actor Eddie Paskey, Lieutenant Leslie must have been "miraculously" revived in an unseen scene, which explains why he's seen again in future episodes, alive and well. However, no such scene exists in the revised final draft script.




published order
Previous episode:
The Gamesters of Triskelion
TOS episode produced Next episode:
The Immunity Syndrome
Previous episode:
The Deadly Years
TOS episode aired Next episode:
Wolf in the Fold
Previous story:
That Which Survives
Star Trek 9
Next story:
The Return of the Archons
chronological order
Previous Adventure:
Beneath the Skin
pages 20-21
Memory Beta Chronology Next Adventure:
Treaty's Law
chapters 1-24
Previous Adventure:
The Gamesters of Triskelion
Pocket Next Adventure:
Treaty's Law
chapters 1-24
Previous Adventure:
The Gamesters of Triskelion
Voyages of the
USS Enterprise (NCC-1701)
(2264 to 2270)
Next Adventure:
The Patrian Transgression

External links

  1. This character was not named in the episode but the same actor, wearing the same operations division Starfleet uniform, was addressed as Vinci in TOS episode: "The Devil in the Dark". The same actor also played the character of Clifford Brent.